1. Field of the Invention
The invention relates to a power supply apparatus, an electronic apparatus, and a power-supply control method, which are particularly suitable for an electronic apparatus, such as a digital light processing (DLP [registered trademark]) projector.
2. Description of the Related Art
Since a large number of electronic apparatuses including various computers require a plurality of stable direct-current voltages from a power supply, DC/DC converters need to be comprised in correspondence with the number of required direct-current voltages.
On the other side, a technology for reducing the number of DC/DC converters is considered (for example, see Jpn. Pat. Appln. KOKAI Publication No. 2008-234842).
Jpn. Pat. Appln. KOKAI Publication No. 2008-234842 discloses a technology configured to provide a light control unit including:
a light source comprising a light emitting part which emits red light, a light emitting part which emits green light, and a light emitting part which emits blue light;
a switching unit connected in series with at least one of solid-state light sources of the light emitting parts;
a variable constant-voltage power supply which is connected in common to the solid-state light sources and drives the light source; and
a switching control unit which switches on/off the switching unit.
When the technology described in the Jpn. Pat. Appln. KOKAI Publication No. 2008-234842 is applied to an apparatus which requires a power supply whose voltage sequentially varies in time series, a voltage value is instable during a period in which the voltage value shifts at the time of switching voltages.
Therefore, in some cases, a load circuit in a following stage cannot be made to perform a desired operation and, for example, control of temporarily stopping the load circuit is required.
Under the circumstances, it is desired to provide a power supply, an electronic apparatus, and a power-supply control method, which are capable of supplying a plurality of rated powers (constant powers) switched at a high speed.